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Topic Review
Biography
Topic Review
Turing Reduction
In computability theory, a Turing reduction from a problem A to a problem B, is a reduction which solves A, assuming the solution to B is already known (Rogers 1967, Soare 1987). It can be understood as an algorithm that could be used to solve A if it had available to it a subroutine for solving B. More formally, a Turing reduction is a function computable by an oracle machine with an oracle for B. Turing reductions can be applied to both decision problems and function problems. If a Turing reduction of A to B exists then every algorithm for B can be used to produce an algorithm for A, by inserting the algorithm for B at each place where the oracle machine computing A queries the oracle for B. However, because the oracle machine may query the oracle a large number of times, the resulting algorithm may require more time asymptotically than either the algorithm for B or the oracle machine computing A, and may require as much space as both together. The first formal definition of relative computability, then called relative reducibility, was given by Alan Turing in 1939 in terms of oracle machines. Later in 1943 and 1952 Stephen Kleene defined an equivalent concept in terms of recursive functions. In 1944 Emil Post used the term "Turing reducibility" to refer to the concept. A polynomial-time Turing reduction is known as a Cook reduction, after Stephen Cook.
4.5K
14 Oct 2022
Topic Review
Smart Grid Management, Control, and Operation
Smart grid management, control and operation (SGMCO) are key tasks for maintaining their proper functioning as well as for their extension and expansion. The current challenges of power generation, distribution, transmission, and consumption, as well as growing energy demand, facilitate the integration of a large number of smart grids with renewable energy generators and physical information systems, while smart grids are moving toward distribution and decentralization in response to the evolving application of the Internet of Energy (IoE). SGMCO handles not only traditional management, control, and operations, but also the future challenges for smart grids: Collaboration between stakeholders, control of network imbalances (e.g. frequency and voltage regulation), data analysis and management, decentralized network management and operation, and security and privacy.
4.5K
10 Jan 2022
Topic Review
AirPort Time Capsule
The AirPort Time Capsule (originally named Time Capsule) was a wireless router sold by Apple Inc., featuring network-attached storage (NAS) and a residential gateway router, and is one of Apple's AirPort products. They are, essentially, versions of the AirPort Extreme with an internal hard drive. Apple describes it as a "Backup Appliance", designed to work in tandem with the Time Machine backup software utility introduced in Mac OS X 10.5. Introduced on January 15, 2008 and released on February 29, 2008, the device has been upgraded several times, matching upgrades in the Extreme series routers. The earliest versions supported 802.11n wireless and came with a 500 GB hard drive in the base model, while the latest model, introduced in 2013, features 802.11ac and a 3 TB hard drive. All models include three Gigabit Ethernet ports and a single USB port. The USB port can be used for external peripheral devices to be shared over the network, such as external hard drives or printers. The NAS functionality utilizes a built-in "server grade" hard drive. On April 26, 2018, Bloomberg News announced that Apple Inc. entire AirPort line had been discontinued without replacement.
4.5K
04 Nov 2022
Topic Review
Math 55
Math 55 is a two-semester long first-year undergraduate mathematics course at Harvard University, founded by Lynn Loomis and Shlomo Sternberg. The official titles of the course are Honors Abstract Algebra (Math 55a) and Honors Real and Complex Analysis (Math 55b). Previously, the official title was Honors Advanced Calculus and Linear Algebra.
4.4K
03 Nov 2022
Topic Review
Country Code Top-Level Domain
A country code top-level domain (ccTLD) is an Internet top-level domain generally used or reserved for a country, sovereign state, or dependent territory identified with a country code. All ASCII ccTLD identifiers are two letters long, and all two-letter top-level domains are ccTLDs. In 2018, the Internet Assigned Numbers Authority (IANA) began implementing internationalized country code top-level domains, consisting of language-native characters when displayed in an end-user application. Creation and delegation of ccTLDs is described in RFC 1591, corresponding to ISO 3166-1 alpha-2 country codes. While gTLD have to obey international regulations, ccTLD are subjected to requirements that are determined by each country’s domain name regulation corporation. With over 150 million domain name registrations today, ccTLDs make up 40% of the total domain name industry. Country code extension applications began in 1985. The registered first extensions that year were .us (United States), .uk (United Kingdom), and .il (Israel). There are 312 ccTLDs in active use totally. .cn, .tk, .de and .uk contain the highest number of domains.
4.4K
08 Nov 2022
Topic Review
Two-Dimensional Space
Two-dimensional space (also known as 2D space, 2-space, or bi-dimensional space) is a geometric setting in which two values (called parameters) are required to determine the position of an element (i.e., point). The set [math]\displaystyle{ \mathbb{R}^2 }[/math] of pairs of real numbers with appropriate structure often serves as the canonical example of a two-dimensional Euclidean space. For a generalization of the concept, see dimension. Two-dimensional space can be seen as a projection of the physical universe onto a plane. Usually, it is thought of as a Euclidean space and the two dimensions are called length and width.
4.4K
28 Nov 2022
Topic Review
Six-Gear Roadmap towards Smart Factory
The fourth industrial revolution is the transformation of manufacturing into smart manufacturing. Advanced industrial digital technologies that make the trend Industry 4.0 are considered as the transforming force that will enable this transformation. However, these technologies need to be connected, integrated and used effectively to create value and to provide insights for data driven manufacturing. Smart manufacturing is a journey and requires a roadmap to guide manufacturing organizations for its adoption. The proposed roadmap is a simple holistic management strategy for an Industry 4.0 implementation journey. It serves as a strategic practical tool for rapid adoption of Industry 4.0 technologies. It bridges the gap between the advanced technologies and their application in manufacturing industry, especially for SMEs.
4.4K
06 Aug 2021
Topic Review
UAV-based IoT
The Internet of Things (IoT), which consists of a large number of small low-cost devices, has become a leading solution for smart cities, smart agriculture, smart buildings, smart grids, e-healthcare, etc. Integrating unmanned aerial vehicles (UAVs) with IoT can result in an airborne UAV-based IoT (UIoT) system and facilitate various value-added services from sky to ground. In addition to wireless sensors, various kinds of IoT devices are connected in UIoT, making the network more heterogeneous. In a UIoT system, for achieving high throughput in an energy-efficient manner, it is crucial to design an efficient medium access control (MAC) protocol because the MAC layer is responsible for coordinating access among the IoT devices in the shared wireless medium. Thus, various MAC protocols with different objectives have been reported for UIoT.
4.4K
07 Dec 2020
Topic Review
Enchanta
Enchanta /ɛnˈtʃɑːntɑː/ (Enchan /ɛnˈtʃɑːn/ in the 2016 series) is a constructed language spoken by the denizens of Encantadia, known as Encantado(s)/Encantada(s) or Diwata (fairies). It was initially created by Suzette Doctolero for the Philippines fantasy television drama saga Encantadia, which aired on GMA Network in 2005, and was later used in the show's sequels, Etheria: Ang Ikalimang Kaharian ng Encantadia and Encantadia: Pag-ibig Hanggang Wakas. The source material of the language appears to have been derived from Philippine languages (particularly Tagalog) and Romance languages. It has its own script, Enchan, which appears to be based on Baybayin. Three songs in the language are written by Doctolero, namely "Asshenti (Love song)", "Hade!! (Etheria theme song)", and "Ivo (Lireo national anthem)", which are all sung by Bayang Barrios for the sequel Etheria in 2006.
4.3K
07 Nov 2022
Topic Review
Internet of Things
The Internet of Things (IoT) refers to a system of interrelated, internet-connected objects that are able to collect and transfer data over a wireless network without human intervention. The term IoT has been considered as an expanding technique applied in various applications and functions, from smart environments and houses to personal healthcare and others [1]. It is described as a smart concept for the internet relating everything to the Internet and data organization and information exchange [2]. The key features required for employing a large-scale IoT are low-cost sensors, highspeed and error-tolerant data communications, smart computations, and numerous applications.
4.3K
26 Oct 2020
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